Method for determining mucosal neutrophil counts in neutropenia patents

Abstract

Based on recent investigations showing iatrogenic, profound neutropenia (and the fever spikes that often accompany it, which must be medicated immediately to avoid the risk of life-threatening infection) can most accurately be monitored by obtaining daily mucosal neutrophil counts from the patient's oral mucosa rather than obtaining daily counts of the patient's blood neutrophils as in the past, a mouth wash method has been developed for collecting muscosal neutrophils. The mouth wash samples so collected are delivered directly, or in aqueous dilution to a sample pad supported on a strip which sample pad has deposited thereon reagents enabling a colorimetric, fluorescent or chemiluminescent assay of the quantity of an enzyme characteristic of human neutrophils that is present in the sample. This measured quantity can be correlated to mucosal neutrophil count. The method shows outstanding sensitivity, precision and accuracy relative to microscopic methods of counting mucosal neutrophils.

Description

INTRODUCTION [0001] The present invention relates to a quick, easy-to-use diagnostic test for monitoring the severity of neutropenia conditions in human patients. BACKGROUND OF THE INVENTION [0002] Neutropenia is a serious deficiency in humans of infection-fighting white blood cells. Its severity has heretofore been tracked by periodic (usually daily) determinations of the individual blood neutrophil count of each patient who is in danger of developing the so-called “profound” or iatrogenic form of this deficiency, which exposes the patient to the danger of developing acute, often life-threatening, bacterial or fungal infection. [0003] Profound or iatrogenic neutropenia, in which the patient is so exposed, most often occurs in two groups of patients, namely (a) individuals who have been subjected to high dose, cytotoxic, anticancer chemotherapy and (b) HIV patients who have either natural or acquired resistance to the protease inhibitors widely used in antiretroviral therapy. [0004]...

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Benefits of technology

[0012] Any of these measurements can be made with simple instruments that are increasingly readily available for such purposes. Correlation of the measurements so obtained to standards that relate observed measurement intensity values to the concentration of human leukocyte enzyme present in samples, and correlation of enzyme content to number of neutrophils present are both achievable. The latter involves comparin, intensity values obtained in the test herein described when it is practiced on samples of known neutrophil count and establishing a correlation curve. Work needed to effect this standard is in progress. Once completed, such correlations can and will be supplied to outpatients and their support groups in the forms of correlation tables, correlation curves, computer programs, etc., as choice may dictate, to enhance the self-administration and nonprofessional or semi professional administration of the tests and enhance understanding of the test results.

[0013] A feature of this invention that lends it greater precision than can be achieved by microscopic counting of neutrophils is that the sample size to be actually measured in each test considerably exceeds that of the two duplicate drops from a suspension of neutrophils and unavoidably associated oral cellular accompaniments (which always include a variable quantity of epithelial cells, microbial flora and cellular debris) upon which neutrophil counts were made by Akpek et al as described at p. 14 of the J. Am. Hematol. paper cited above. Currently ongoing testing to ascertain details of the sample size to be specified in test kits designed to be utilized by persons lacking laboratory training exhibits highly promising trends relative to the outstanding precision and accuracy of this test as herein described and envisioned to be further refined. While the present test is aimed at persons without laboratory training, it is envisioned that its specificity, precision and accuracy may render its use attractive to professionals working in hospital settings and enable elimination of many instances of counting neutrophils under a microscope that are now required in the treatment of iatroginic neutropenia.

Problems solved by technology

In many cases, these adjunct improvements have enabled the administration of high dose anticancer chemotherapy to be moved from the hospital to outpatient settings, where daily blood count monitoring is not easily accomplished.

Studies of neutrophil kinetics showed, as early as the 1980's, that neutrophil blood counts do not uniformly and consistently reflect the neutrophil population on extravascular surfaces where the principal work of repelling infectious bacteria and fungi is effected by neutrophils.

It is noted, however, that no studies of mucosal neutrophil counts appear to have been made relative to HIV patients with profound neutropenia.

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